A Key-Ladder is a generic cryptographic construction used mostly in the content distribution domain. Typically, it comprises chaining of keyed cryptographic operations, such that each one of those operations gets its key from the output of the previous operation. The input for all operations in a key ladder is typically provided from outside of the key ladder. The highest (i.e., the first) level of the key ladder typically gets its key from the hardware itself (for example and without limiting the generality of the foregoing, from One-Time-Programmable [OTP] memory). The lowest (i.e. the final) level of the key ladder typically outputs its result out of the key-ladder for general use—for example, for decrypting encrypted content or other appropriate ciphertexts. Key-ladder intermediate levels generate varying levels of intermediate service-keys, which are typically refreshed in decreasing frequency: i.e., never, yearly, monthly, weekly, daily, etc. Alternatively, each of these intermediate keys may be provided by different entities.